1. Field of the Invention
This invention relates to beverage coolers, and more particularly to a portable cooler for chilling a beverage.
2. Description of the Prior Art
Various devices are known for keeping a beverage in a chilled state. These include a cup having polystyrene insulating walls. The rate at which the main body of the beverage absorbs heat from the environment is reduced, but the cup is ineffective to chill the beverage.
U.S. Pat. No. 4,357,809 discloses a beverage holder in which a peripheral annular wall compartment contains a freezable refrigerant to cool the beverage in the holder. However, there is a substantially direct absorption of heat from the environment by the refrigerant because one side of the wall compartment forms the outside of the holder. In addition, the thickness of the wall compartment makes the holder too bulky for convenient use as a portable drinking utensil. Moreover, the entire holder must be placed in a refrigerator to cool the refrigerant.
A replaceable refrigerant capsule is disclosed in U.S. Pat. No. 3,840,153. The capsule fits within a beverage chamber defined within a flexible or squeezable drinking utensil. A dispensing tube is also located in the beverage chamber in spaced apart relation to the refrigerant capsule. The cooled beverage is discharged from the tube when the utensil is squeezed.
A major drawback of this design is that there is only localized cooling of the beverage adjacent the refrigerant capsule and the beverage must be continuously agitated or mixed to provide uniform cooling. The design undesirably comprises a considerable number of components which are costly to manufacture and assemble and inconvenient to clean.
It is desirable for a beverage cooler to provide specific or localized cooling of the beverage portion being dispensed to a temperature below the temperature of the main body of the beverage. It is also desirable that the cooler comprise relatively few components which can be easily manufactured and assembled, and which are easy to clean.